The present invention relates to compositions and kits for and methods of detecting metastasized colorectal tumor cells in samples. The present invention also relates to compositions and kits for and methods of evaluating the extent of invasive activity of colorectal tumor cells in samples from the colon.
Colorectal cancer is the third most common neoplasm worldwide and the second most common in the United States, representing about 15% of the newly diagnosed cases of cancer in the United States. The large intestine or large bowel is the third leading site for the development of new cancer and is diagnosed in about 150,000 patients each year. Colorectal cancer is the second leading cause of cancer-related deaths and is responsible for about 12% of cancer deaths in the United States. The mortality rate of newly diagnosed large bowel cancer approaches 50% and there has been little improvement over the past 40 years. Most of this mortality reflects local, regional and distant metastases. About thirty percent of patients with colorectal cancer have unresectable disease at presentation and about 40% develop metastases during the course of their disease. Distant metastatic disease is seen in liver (about 12%), lung (about 3%), bone (about 0.9%), brain (about 0.7%) , nodes (about 4%) , and peritoneum (about 2%) at the time of initial diagnosis. In 1987, the large bowel cancers found regionally or at distant sites at the time of diagnosis were about 26% and about 18%, respectively.
Surgery is the mainstay of treatment for colorectal cancer but recurrence is frequent. Colorectal cancer has proven resistant to chemotherapy, although limited success has been achieved using a combination of 5-fluorouracil and levamisole. Surgery has had the largest impact on survival and, in some patients with limited disease, achieves a cure. However, surgery removes bulk tumor, leaving behind microscopic residual disease which ultimately results in recrudescence. Overall recurrence rates for colonic tumors are about 33% and for rectal cancer about 42%. Of these recurrences, about 9% are local, about 13% are systemic metastatic disease, and the remaining 88% are a combination of local and systemic disease. Fifty percent of patients with recurrent colorectal cancer have hepatic metastases.
Early detection of primary, metastatic, and recurrent disease can significantly impact the prognosis of individuals suffering from colorectal cancer. Large bowel cancer diagnosed at an early stage has a significantly better outcome than that diagnosed at more advanced stages. The 5 year relative survival rates for patients with regional or distant metastases are 48% and 5%, compared with 90% and 77% for disease which is in situ or local, respectively, at the time of diagnosis. Similarly, diagnosis of metastatic or recurrent disease earlier potentially carries with it a better prognosis.
Immunoscintigraphy using monoclonal antibodies directed at tumor-specific markers has been employed to diagnose colorectal cancer. Monoclonal antibodies against carcinoembryonic antigen (CEA) labeled with 99Technetium identified 94% of patients with recurrent tumors. Similarly, 111Indium-labeled anti-CEA monoclonal antibodies successfully diagnosed 85% of patients with recurrent colorectal carcinoma who were not diagnosed by conventional techniques. 125Iodine-labeled antibodies have been effective in localizing more than 80% of the pathologically-confirmed recurrences by intraoperative gamma probe scanning.
There remains a need for compositions and kits which can specifically detect metastasized colorectal cancer cells using samples removed from or discharged by an individual being screened for, suspected of suffering from of suspected of being susceptible to metastasized colorectal tumors. There remains a need for methods of identifying individuals suffering from metastasized colorectal tumors using samples removed from or discharged by an individual being screened for, suspected of suffering from or suspected of being susceptible to metastasized colorectal tumors.
The present invention relates to in vitro methods of determining whether or not an individual has metastasized colorectal cancer cells. The present invention relates to in vitro methods of examining samples of non-colorectal tissue and body fluids from an individual to determine whether or not ST receptor protein, which is a protein that is specific to colorectal cells including colorectal tumor cells, is being expressed by cells outside of the colorectal track. The presence of the ST receptor protein or of nucleic acid molecules that are indicative of expression of the ST receptor protein is evidence that the individual is suffering from metastasized colorectal cancer.
The present invention relates to in vitro methods of determining whether or not tumor cells are colorectal in origin. The present invention relates to in vitro methods of diagnosing whether or not an individual suffering from cancer is suffering from colorectal cancer. The present invention relates to in vitro methods of examining samples of tumors from an individual to determine whether or not ST receptor protein, which is a protein that is specific to colorectal cells including colorectal tumor cells, is being expressed by the tumor cells. The presence of the ST receptor protein or of nucleic acid molecules that are indicative of expression of the ST receptor protein is evidence that the individual is suffering from colorectal cancer.
The present invention relates to in vitro kits for practicing the methods of the invention and to reagents and compositions useful to practice the methods, for example as components in such in vitro kits of the invention.
In some embodiments of the invention, non-colorectal tissue and fluid samples may be screened to identify the presence or absence of the ST receptor protein. Techniques such as an ST receptor/ligand binding assays, ELISA assays and Western blots may be performed to determine whether the ST receptor is present in a sample.
In some embodiments of the invention, non-colorectal tissue and fluid samples may be screened to identify whether ST receptor protein is being expressed in cells outside of the colorectal track by detecting the presence or absence of MRNA that encodes the ST receptor protein. The presence of mRNA that encodes the ST receptor protein or CDNA generated therefrom can be determined using techniques such as PCR amplification, Northern Blots (mRNA), Southern Blots (cDNA), or oligonucleotide hybridization.
In some embodiments of the invention, cells of non-colorectal tissue samples may be examined to identify the presence or absence of the ST receptor protein. Techniques such as an ST receptor/ligand binding or immunohistochemistry blots may be performed on tissue sections to determine whether the ST receptor is present in a sample.
In some embodiments of the invention, cells of non-colorectal tissue samples may be examined to determine whether ST receptor protein is being expressed in cells outside of the colorectal track by detecting the presence or absence of MRNA that encodes the ST receptor protein. The presence of MRNA that encodes the ST receptor/protein or CDNA generated therefrom in cells from tissue sections can be determined using techniques such as in situ hybridization.
Another aspect of the invention relates to methods of analyzing tissue samples from the colon tissue to evaluate the extent of metastasis or invasion of colorectal tumor cells into the laminapropria. The laminapropria represents the barrier between the colorectal tract and the rest of the body; see Bailey""s Textbook of Histology, 16th edition, Coperhaven et al. 1975 Williams and Wilkens, Baltimore, Md. at page 404 which is incorporated herein by reference. By identifying the presence of ST receptor or mRNA that encodes ST receptor protein in cells of the laminapropria, the extent of invasion/infiltration of colorectal tumor cells into non-colorectal tissue can be evaluated and confirmed.
The present invention relates to in vitro kits for evaluating tissues samples to determine the level of metastasis and to reagents and compositions useful to practice the same. In some embodiments of the invention, tissue samples which include sections of the laminapropria may be isolated from individuals undergoing or recovery from surgery to remove colorectal tumors. The tissue is analyzed to determine the extent of invasion into the basement membrane of the laminapropria by neoplastic colorectal cells. Identification of the presence or absence of the ST receptor protein confirms evaluation of the migration of tumor cells into the basement membrane indicating metastasis. Techniques such as an ST receptor/ligand binding and immunohistochemistry assays may be performed to determine whether the ST receptor is present in cells in the tissue sample which are indicative of metastatic migration. Alternatively, in some embodiments of the invention, tissue samples that include the laminapropria are analyzed to identify whether ST receptor protein is being expressed in cells in the tissue sample which indicate metastatic migration by detecting the presence or absence of MRNA that encodes the ST receptor protein. The presence of MRNA that encodes the ST receptor protein or cDNA generated therefrom can be determined using techniques such as in situ hybridization.